Low-dose versus high-dose intravenous nitroglycerin in the treatment of sympathetic crashing acute pulmonary edema: A systematic review and meta-analysis focusing on efficacy, safety, and outcomes

Backgound Sympathetic crashing acute pulmonary edema (SCAPE) is a menacing medical emergency that manifests as a severe conundrum of acute heart failure (AHF), characterized by an increase in systemic vascular resistance, which results in rapid redistribution of fluid to the pulmonary circulation. While the use of high-dose nitroglycerin (NTG) is gaining traction amid this patient subset, evidence on its efficacy and safety remains scarce and therefore lack of accuracy. Our aim was to compare the efficacy and safety between high- and low-dose NTG in patients with SCAPE. Methods A systematic literature search was conducted using PubMed, Europe PMC, and ScienceDirect for trials comparing the outcomes of high-dose NTG in SCAPE patients to low-dose NTG. Pre-defined efficacy (symptoms resolution rate within 6 hours, mechanical ventilation rates, length of hospital stay, major adverse cardiovascular events (MACE)) and safety outcomes were summarized throughout the studies. Results A total of 4 studies involving 185 participants were included. Compared to low-dose NTG, high-dose subset appeared to result in shortened hospital length of stay and faster symptoms alleviation within 6 hours of admission. The primary combined endpoint of mechanical ventilation was notably reduced in high-dose as compared to low-dose group. There was no statistically significant difference in MACE risk between high- and low-dose subgroups. No adverse event (hypotension) was observed in both groups. Conclusion Current evidence suggests that high-dose NTG (≥100 mcg/min) delivers a modest but superior improvement in several clinical parameters and is a viable alternative to low-dose NTG in the management of SCAPE patients.